Questions tagged [cp-m]
For questions related to the CP/M operating system by Gary Kildall.
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What's the earliest source for the legend of Gary Kildall's airplane snub?
A commonly repeated (and commonly debunked) legend describes how Gary Kildall blew his chance at writing the operating system for the IBM PC. Examples include the following:
…legend has it that ...
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How do I properly exit a program and return to the CCP in CP/M?
Once my CP/M program has finished doing whatever it's supposed to do, or the user chooses some sort of "quit" option, how do I return the user back to the CCP? Can I just do a ret? Or do I ...
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Z80 to 68000 translator for CP/M
CP/M was mostly portable across systems but most of them were z80 based. It was ported to 8086, 68000 and maybe more but without binary compatibility.
No z80 systems that wanted CP/M compatibility ...
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In CP/M, how did a program know when to load a particular overlay?
Here is what I understand so far:
A program that was too large to put into main memory was broken into several overlay regions. Once you needed data from outside of the currently loaded region, ...
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Are any CP/M systems still in commercial use today?
I understand that there is a great deal of mainframe-era enterprise software that is still in active use, if not on the original hardware then in emulated environments. Its users keep it running ...
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Long Term Prevalence of 8080 Code Over Z80 Code in Software Packages
TL;DR:
The Z80 was introduced not long after the 8080 and replaced it quickly and almost entirely for personal computing. Still, a large chunk of new software written stayed with 8080 code, making no ...
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2
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Was the S-83 Personal CP/M CPU used in commercial computers?
The June 1984 edition of Practical Computing magazine (page 43) refers to the American Microsystems Incorporated S-83 CPU as a Z80 compatible CPU with an 8K mask ROM capable of holding Digital ...
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Is there a digital version of the CP/M T/Maker manual available?
I have a CP/M emulator running on a Raspberry Pi. I managed to run the old circa 1979 T/Maker program, but I don't have a manual. Any thoughts on where I can find one?
6
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CONIN (Console In) in CP/M and "old characters" in character latch
CP/M uses CONIN to read a single character from the keyboard, and it will assert CONST to poll the status register for incoming characters. Let's assume the keyboard controller can buffer one ...
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9
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What was FDOS an abbreviation for in CP/M?
Digital Research wrote in the CP/M manual that
"The BIOS and BDOS are logically combined into a single module with a common entry point and referred to as the FDOS. "
What is FDOS an ...
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How do you run a program automatically when CP/M 2.2 loads?
Following my question on booting CP/M automatically on RC2014 Z80, I'd like to run a program after CP/M starts, similar to how autoexec.bat works on DOS.
I see that CP/M 3 has PROFILE.SUB which would ...
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2
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1
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Why does Z80 RC2014 ROM image 88 not have CP/M or BASIC boot options?
While trying to boot to CP/M automatically on my RC2014 Z80, I encountered a problem getting SCM to show a CP/M boot option. According to the docs, ROM address 4000 (88 on the ROM label) is SCM with ...
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13
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3
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How many characters/pages could WordStar hold on a typical CP/M machine?
I was looking at the Atari Word Processor which could hold only about one or two pages in 48k memory due to it requiring DOS to be loaded along with the relatively large program itself.
That led me to ...
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10
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Is there any known magic number signature for CP/M-80 program files?
I'm looking for a way to identify CP/M-80 (i.e. 8080 code) program files (.COM) from their content. A process usually known as Magic Number or File Signature detection, intended to identify a file by ...
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7
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Why didn't the CP/M-86 assembler support traditional macros?
The ASM86.CMD assembler Digital Research shipped with CP/M-86 provided only code-macros, a limited type of macros for creating new instructions through a small set of specific directives. Why didn't ...
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